Radio transmitter control



Dec. 30, 1952 P. E. FISCHLER ET AL RADIO TRANSMITTER CONTROL.

Filed June 28, 1949 3 Sheets-Sheet l D\ 9|. Pousma INVENTORB PAUL E F/SCHLER PAUL J THUT ATTORNEYS Dec. 30, 1952 P. E. FISCHLER ET AL 2,623,992

RADIO TRANSMITTER CONTROL Filed June 28, 1949 5 Sheets-Sheet 2 IN VEN TORS PAUL E. F/SCHLER PAUL J THU T BY 7 v ATTORNEYS 3 Sheets-Sheet 3 P. E. FISCHLER ET AL RADIO TRANSMITTER CONTROL IN V EN TORS PAUL E. FISCHL 5/? PA UL J. THU 7' A TTORNEVS Dec. 30, 1952 Filed June 28, 1949 disclosure is Patented Dec. 30, 1952 RADIO TRANSMITTER ooNTRoL Paul E. 'Fischler, Buffalo, and Paul John Thut,

East Rochester, N.

Y., assignors to Technical Alliance, Inc., a corporation Application June 28, 1949, Serial No. 101,844

6 Claims.

This invention relates to a radio transmittter control and more particularly to a radio transmitter of the type commonly called a pull-box, for use where it is desired to transmit a series of audio impulses.

Such devices are particularly well adapted for use in connection with fire alarm systems of the type described in the copending application, Serial Number 30,923, filed June 3, 1948, but may be used for other purposes.

An object of the invention is to provide a transmitter" of the type described of compact construction, so that it may be readily mounted in the usual pull-box commonly employed with fire alarm systems and the like, the transmitter being entirely self contained, including the power upp y.

Another object is to provide a radio transmitter enclosed in a casing having a main door which may be locked and an auxiliary door which may be opened by the public in order to operate the release lever to actuate the mechanism in the casing'to automatically send in the alarm.

Another object is to provide a device of the character described having a motor driven timer unit adapted to first connect the power supply to the transmitter and allow sufiicient time for the tubes in the transmitter to warm up, and then release the pulsing mechanism which pulses the carrier wave, thereby indicating which box is sending in the signal to the centrally located receiver from which the alarm may be broadcast.

A further object is to provide a simple motor driven timer having few parts and which may be removed from the box as a unit.

Other objects and advantages will be apparent from the following specification where, for example, is shown a preferred embodiment of the invention suitable for use with the fire alarm systems disclosed in the aforesaid copending application.

It will be understood, however, that the instant merely illustrative and not limitative of the invention which is as defined in the appended claims.

Referring to the accompanying drawings:

Figure l is a front view of a radio transmitter hereinafter termed a pull-box, embodying the invention;

Figure 2 is a front view of the auxiliary door of the pull-box shown in Figure 1, said auxiliary door being opento show the. release lever mounted on the main door of the box;

Figure 3 is a partial view of the inside of the main door of the box shown in Figure 1, showing the inner end of the release lever;

Figure 4 is a view of the interior of the box, Figure 1, the main door being open;

Figure 5 is a top view of the motor driven timer mechanism used in the box, Figure 1, with the driving spring omitted;

Figure 6 is a diagrammatic side view of the mechanism shown in Figure 5, with the driving spring and its shaft and gear omitted; and

Figure '7 is circuit diagram of the radio transmitter shown in Figure 1.

Referring to Figure 1, the numeral Ill denotes the usual fire alarm box containing all of the apparatus hereinafter described.

The box has a main door H which is provided with a lock l2 so that after the pulsing dial is preset as hereinafter described after each use, the door is locked by the fireman so that the public cannot gain access to the interior of the box.

The main door II is provided with an auxiliary door l3 which is hinged at the bottom at I4 and provided with a spring l5 which urges the door to closed position, so that normally the outer end of the release lever [B to be presently described is protected from the elements.

The release lever has a frame H which is secured within the main door, the inner surface of which is shown at l8, Figure 3, and the ears [9 of the release lever firmly support the irmer portion 20 of the release lever. A spring 2| is positioned between the release lever and its support so that the outer end of the release lever is always held up in the position shown in Figure 2. The release lever carries a laterally extending pin 22 adapted to engage and trip the power driven timer unit to be presently described.

Inside the box ID is mounted a panel 23 behind which is mounted, in any suitable manner, the oscillator, amplifier and modulator for the transmitter, connected as shown in Figure 7. These may be of any desired type and, as their construction is Well known, they will not be here-' in described in detail.

Also mounted on this panel 2 3 is a motor driven timer unit 24, a gong 25 and the pulsing means 26. The latter can be an ordinary telephone dial such as commonly employed in automatic telephone systems.

The space 2'! in the box may be utilized for the batteries or other power supply for the transmitter. The timer mechanism 24 may be motor driven and any suitable form of motor may be used, such as an electric motor or spring motor.

If an electric motor is used, a suitable switch, not shown, starts the motor when the release lever It is operated. For the sake of simplicity, however, the motor will be described as a spring motor and the spring is omitted from the drawings, it being sufficient to state that the spring is wound up by means of the key 28 on its shaft in the usual way, the fixed end of the spring being secured to an anchor pin on a fixed part of the casing in the usual manner,

The first driving wheel in the gear train shown in Figure is indicated at 29 and drives a pinion 30 mounted on a shaft 3! carrying cams 32, 33 and a gear 34 meshed with the pinion 35 on shaft 36 carrying the escape wheel 31. V

The escape wheel 37 engages theteeth of the double pawl 38 which has a bifurcated end at '39 engaging the strike lever 40, carrying the usual ball 4| adapted to strike the gong 25 positioned adj acent thereto.

It will be observed that the parts so far described constitute a spring motor which may be of any desired construction and which will, when released, operate at a speed determined by the escapement 31, 38.

The cam 32 carries a pin 43 adapted to engage the notch 42 in theupper end of the lever 44 pivoted at 45, and having a laterally extending arm 46 carrying an outwardly extending pin adapted to be engaged by the pin 22 of the release lever.

Obviously, as long as the pin 43 is in the notch in lever 44, the device will not operate, but as soon as the pin 47 is raised upwardly by pulling down on the release lever [5, pin 43 moves out of the slot in the arm 44 and the cam 3! is revolved in the direction of the arrow thereon and will make one revolution.

The arm 44 is urged to the left by means of spring 48 and lies in the path of revolution of pin 43, which strikes the slanting nose of the lever 44 and drops into the slot therein, stopping the operation of the device after one complete revolution of the cams.

It will be seen that as soon as the device is released to operation, the cam 33 releases a switch 49, thereby closing the power circuit to the oscillator, amplifier and modulator of thetransmitter, which remains closed duringone revolution of said cam, until the parts assume the relative position shown in Figure 6, whereupon the circuit through switch 49 is again opened and re-v mains open while the device is not in operation.

About four seconds after the operation of switch 49, cam 32 engages the roller 50 on the lever 5| which operates the pawl 52, withdrawing same from the slot 53 in the'edge of the dial 25, which has been pre-set to the desired number. This releases the dial and the contacts therein pulse the oscillator of the transmitter in a known manner, and the transmitter'acc-ording1y broadcasts the desired number.

During. the entire operation just described, the gong 25 is being struck so that the person-sending in the alarm will know that the mechanism is in operation. The spring has sufficient energy to operate the device about 20 times without any appreciable slowdown and it will be observed that, even should the device slow down, the ope-ration of the timer mechanism 24 is not affected, as this is accomplished by the wound-up spring in the dial 26 which is pre-set after each operation.

It will be observed'that the notch 53 in the pull down the auxiliary door l3, pull down the release lever l6, thereby starting the operation 01' the unit 24 which first Will close switch 49 to supply current to the transmitter tubes and then,

aftersaid tubes are in operating condition, the

unit will release the dial 26 to send in the proper 7 signal.

Upon arrival at the box, the fireman will unlock same and re-set the dial 26 and if necessary, re-wind the unit by means of the key 28.

It will be observed that the unit 24 needs only two wires for its operation, namely, thoseg-oing to the switch 49, and that same may be removed for inspection and repair and replaced without disturbing the connections to the dial '26 or any or the transmitter connections.

What is claimed is:

l. A radio transmitter comprising an oscillator, amplifier and modulator and a source of current all interconnected to produce an audio modulated carrier wave to be broadcast; a casing for said transmitter having a main door; a release lever mounted on said door and extending outwardly therefrom and into said casing; an auxiliary door mounted on said main door and enclosing the outer end of said lever; power-driven means within said casing including a switch for controlling the application of said source of current tosaid oscillator, amplifier and modulator, said means being mechanically interconnected to said lever for release thereby; means connected to said power-driven means adapted upon operation thereof to pulse said carrier wave including a manually settable dial adapted to be presetand so held; and means controlled by said powerdriven means for holding said dial in said preset position until released by the operation of said power-driven means.

2. In a radio transmitter, a motor driven timer, a control mechanismadapted to lock said timer against operation, a manually operable'release lever, means controlled by said lever to. mechanically release said timer to cause said control mechanism to make a single revolution and return to locked position, a switch for controlling the operation of said transmitter operatively controlled by saidmechanism and manually resettable pulsing means controlled by said mechanism.

3. In combination, abox-like casing having a door; a panel mounted within said casing; a radio transmitter mounted on said panel; a release lever mounted on said door and extending into said casing; door and said lever and tending to hold said lever in a non-operating position; a power-driven'device mounted on said panel and adapted to be mechanically engaged and released for operation by said lever; a power supply; a switch operated by said power-driven deviceior connecting said power supply to said transmitter; aspring operated pulsing device on said panel and-connected to said transmitter; and means ope'rated by said power-driven device for releasing said pulsing device to pulse said transmiter; said pulsing device comprising arotary' dialhaving a spring extending between-said a notch therein, and said power driven devices including a pawl normally engaging said notch to hold said dial ready for operation upon the withdrawal of said pawl by the operation of said power driven device.

4. In combination with a radio transmitter, a power driven device adapted for cyclic operation, mechanical means adapted to lock said device against operation, a manually operable release lever adapted when moved to mechanically release said means to permit said device to operate, a switch adapted to be closed by said device to connect a source of operating current to said transmitter for a predetermined period of time and then disconnect the same, a, spring operated pulsing device for pulsing said transmitter cyclically controlled by said power driven device and adapted to pulse said transmitter fo at least a portion of the time said switch is closed, and means for manually setting said pulsing device to deliver a predetermined number of pulses at each operation.

5. In a device of the character described, a radio transmitter, a circuit connected to said transmitter including a source of current for the operation thereof, a normally open switch in said circuit, a manually settable spring operated a wall thereof.

PAUL E. FISCHLER. PAUL JOHN THUT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,479,608 Jackson Jan. 1, 1924 2,151,272 Hayes Mar. 21, 1939 2,214,101 Cumming Sept. 10, 1940 FOREIGN PATENTS Number Country Date 550,430 Great Britain Jan. 7, 1943 

